DESCRIPTION (taken for application): This Core will be responsible for developing mathematical models and algorithms to describe and predict the physiology and pathophysiology of the various systems to be studied by the four projects in this application. The systems to be studied are quite diverse ? ranging from cells to tissue samples to organs to entire animals. As such the range of mathematical models will be concomitantly quite large. The goal of this Core is thus not to provide a detailed precis of all possible models, but rather to discuss the classes of mathematical descriptions that will be available to the individual investigators, and importantly, the variety of methods that will be employed to gain scientific insight from the modeling process.